H1N1 Mortality Found to Be Unexpectedly Low in England

But authors recommend wider vaccination program, point out importance of antiviral drugs

By Rick Ansorge

HealthDay Reporter

FRIDAY, Dec. 11 (HealthDay News) -- In England, mortality from the H1N1 pandemic is lower than expected, but disease patterns suggest that the vaccination program should be extended beyond high-risk groups, according to a study published online Dec. 10 in BMJ.

Liam J. Donaldson, M.D., chief medical officer for England at the Department of Health in London, and colleagues investigated all 138 reported pandemic-related deaths in England from the beginning of 2009 through Nov. 8.

Overall, the researchers identified a case-fatality rate of 26 per 100,000. Although the attack rate was highest in children and lower in older adults, they found that the case-fatality rate was significantly lower among children aged 5 to 14 years than among adults over age 65 (11 versus 980 per 100,000). They also found that 67 percent of the patients who died would currently be eligible for the first phase of vaccination, and that 36 percent of the fatalities either had no, or only a mild, pre-existing illness. The authors further note that 78 percent of the patients who died had been prescribed antiviral drugs, but, of these patients, 76 percent did not receive the drugs within the first 48 hours of being ill.

"Our findings lend support to a vaccination strategy that prioritizes high risk groups," the authors write. "They also show that a substantial minority of deaths are occurring outside these groups. Wider population vaccination therefore merits consideration. Cost benefit analyses could further assist these decisions. These are difficult to conduct and to interpret in the uncertain context of an evolving pandemic."